WTP-GC,
Consider what might happen with the Anderson Jack if it had broken as my levelers did. I don't think that is off topic at all. I should have perhaps been clearer, and provided more information in my original post to the thread.
Initially I thought the levelers were the cat's meow, but being cautious I kept my boards in storage.
I was inside when the RV when the first one failed--It make a heck of a noise. Because the one that failed was on the inside dual I did not find out until I moved the RV. The second failure happened when I was asleep--and it woke me up.
The levelers were narrower than the width of my tires and when at their height limit pressed sharply into the tires. They tend to slide if the ground is wet.
I know of 3 other rv'ers who have had leveler failures. The product looks great but doesn't perform flawlessly. In one case the user has had several replacements and even some replacements for those replacements.
I was in one situation where I had to add boards beneath the Anderson Levelers, because they did not raise the RV enough.
The bottom line is I would not trust the Anderson Jack to not fail.